/*
    Copyright (c) 2009, Interactive Pulp, LLC
    All rights reserved.
    
    Redistribution and use in source and binary forms, with or without 
    modification, are permitted provided that the following conditions are met:

        * Redistributions of source code must retain the above copyright 
          notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above copyright 
          notice, this list of conditions and the following disclaimer in the 
          documentation and/or other materials provided with the distribution.
        * Neither the name of Interactive Pulp, LLC nor the names of its 
          contributors may be used to endorse or promote products derived from 
          this software without specific prior written permission.
    
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
    ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
    POSSIBILITY OF SUCH DAMAGE.
*/

package pulpcore.net;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.Iterator;
import java.util.Map;
import java.util.List;
import java.util.ArrayList;
import pulpcore.Build;
import pulpcore.CoreSystem;
import pulpcore.util.ByteArray;

/**
    The Upload class represents name/value pairs for sending to an HTTP server 
    via the POST method (multipart form). Values can be either plain text or files.
*/
public class Upload {
    
    private static final int BUFFER_SIZE = 1024;
    private static final String NEW_LINE = "\r\n";

    private URL url;
    private List fields;
    private String formBoundary;
    private String response;
    private boolean completed;
    private IOException uncaughtException;
       
    /**
        Creates a new Upload object.
        @param url the URL to send the POST to.
    */
    public Upload(URL url) {
        this.url = url;
        fields = new ArrayList();
        formBoundary = "PulpCore-Upload:" + System.currentTimeMillis();
    }
    
    /**
        Adds plain text form fields to this form. 
    */
    public void addFields(Map fields) {
        Iterator keys = fields.keySet().iterator();
        while (keys.hasNext()) {
            String name = keys.next().toString();
            addField(name, fields.get(name).toString());
        }
    }    
    
    /**
        Add a plain text form field to this form. 
    */
    public void addField(String name, String value) {
        
        String field = "--" + formBoundary + NEW_LINE +
            "Content-Disposition: form-data; " +
            "name=\"" + name + "\"" + NEW_LINE + NEW_LINE +
            value + NEW_LINE;

        fields.add(getBytes(field));
    }
    
    /**
        Add a data file to this form. 
    */
    public void addFile(String name, String fileName, String mimeType, byte[] fileData) {
        
        String header = "--" + formBoundary + NEW_LINE +
            "Content-Disposition: form-data; " +
            "name=\"" + name + "\"; " +
            "filename=\"" + fileName + "\"" + NEW_LINE +
            "Content-Type: " + mimeType + NEW_LINE +
            "Content-Transfer-Encoding: binary" + NEW_LINE + NEW_LINE;

        ByteArray out = new ByteArray(header.length() + fileData.length + NEW_LINE.length());
        out.write(getBytes(header));
        out.write(fileData);
        // is this newline needed?
        out.write(getBytes(NEW_LINE));
        
        fields.add(out.getData());
    }
    
    private byte[] getBytes(String field) {
        try {
            return field.getBytes("ISO-8859-1");
        }
        catch (UnsupportedEncodingException ex) {
            return field.getBytes();
        }
    }

    private class Runner implements Runnable {
    
        public void run() {
            try {
                send();
            }
            catch (IOException ex) {
                if (Build.DEBUG) CoreSystem.print("Upload", ex);
                response = null;
                completed = true;
                uncaughtException = ex;
            }
        }
    }
    
    /**
        Write the form to an URL via the POST method.
        The form is sent using the multipart/form-data encoding. 
        The response, if any, can be retrieved using getResponse().
        This method makes the request asynchronously (returns immediately).
    */
    public void start() {
        completed = false;
        new Thread(new Runner(), "PulpCore-Upload").start();
    }
    
    /**
        Write the form to an URL via the POST method. 
        The form is sent using the multipart/form-data encoding. 
        The response, if any, can be retrieved using getResponse().
        @param asynchronous true for asynchronous operation
        (the call returns immediately) or false for synchronous operation (the call
        blocks until the method is complete or an error occurs).
    */
    public void start(boolean asynchronous) {
        if (asynchronous) {
            start();
        }
        else {
            new Runner().run();
        }
    }
    
    private void send() throws IOException {
        completed = false;
        URLConnection connection = url.openConnection();

        if (connection instanceof HttpURLConnection) {
            HttpURLConnection c = (HttpURLConnection)connection;
            c.setRequestMethod("POST");
        }
        connection.setDoInput(true);
        connection.setDoOutput(true);
        connection.setUseCaches(false);
        connection.setRequestProperty("Content-Type",
            "multipart/form-data, boundary=" + formBoundary);

        // Send form data
        OutputStream out = connection.getOutputStream();
        for (int i = 0; i < fields.size(); i++) {
            out.write((byte[])fields.get(i));
        }

        out.write(getBytes("--" + formBoundary + "--"));
        out.flush();
        out.close();

        // Get response data.
        BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
        StringBuffer responseBuffer = new StringBuffer();
        char[] buffer = new char[BUFFER_SIZE];
        while (true) {
            int charsRead = in.read(buffer);
            if (charsRead == -1) {
                break;
            }
            responseBuffer.append(buffer, 0, charsRead);
        }

        in.close();

        if (Build.DEBUG) {
            URL newURL = connection.getURL();
            if (!url.toString().equals(newURL.toString())) {
                CoreSystem.print("Note: POST redirected to: " + newURL);
            }
        }

        this.response = responseBuffer.toString();
        this.completed = true;
    }

    /**
        @return the response string.
    */
    public String getResponse() {
        return response;
    }
    
    /**
        @return true if a call to start() has completed.
    */
    public boolean isCompleted() {
        return completed;
    }

    /**
        @return the uncaught exception during upload, if any.
    */
    public IOException getUncaughtException() {
        return uncaughtException;
    }
}
